Although.. some genes are said to have 'markers' or hets that do look different. For example.. I think it is ivory bloods.. a het ivory is a 'marble' blood.

That may just be a co-dominant trait though. Markers are controversial.. some morphs like granite burms have some hets that show 'markers' and some that don't, so then it gets REALLY confusing.

Co-dominant is where the het form (one copy of the gene) of the gene is different from normal (ie pastel) and the homozygous form (two copies of the gene) is even different from the het form (super pastel)

In retics there is tiger, and super tiger.. etc etc.